Carburetor



Oct.. 6, 1936.

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' E. D. WALLACE CARBURETOR Filed Oct. 19, l1964 E; EDWaliace 2Sheets-Sheet l Gttomeg Oct. 6, 1936.

E. D. WALLACE CARBURETOR v 2 .SheeJcS-Sheet 2 Filed Oct. 19, 1934 Fig. 3l

` 3nventor.,

Ellwallace i mg. W (lttorneg Patented Oct. 6, 1936 UNITED STATES PATENToFFlcE CARBURETOR Application October 19, 1934, Serial No. 749,118

5 Claims.

The present invention relates to carburetors for internal combustionengines and thelike, and has for an object to provide an improvedstructure for more effectively completing the volatilization of thefuel, such as raw gasoline so as toprovide a better vaporized mix of thehydrocar- 4bon and air than with present used devices.

Another object of the invention is to provide a device of this characterwhich may be used on different types of internal combustion engines andalsowith varioustypes of liquid fuels so as to obtain the best possibleresults from the -fuels and in the din'erent'types of engines.

The invention has for a further object the provision of an improvedlmeans for initially` heating and'vaporizing the liquid" fuel prior toits admixture with` the main body of air and prior to its delivery tothe intake manifold of the engine, andto provide various means forcontrollingthe vaporization of the fuel and the quantity thereof foradmixture with theair.

With the foregoing and-,other objects in View, the inventionV will bemore fully described lhereinafter, and will be more particularlypointedr out in the claims appended hereto.

In the drawings, ,wherein like symbols refer to like or correspondingparts throughout the severalviews,

Figure l'is an enlarged vertical ysectional view taken through acarburetor constructed Vaccord-r ing to the present invention, thesection being taken substantiallyon the line I -I of Figure 3.

Figure 2 is .a horizontal section taken through the carburetor on theline 2-2 of Figure 1, and

Figure is a top plan viewl of the device.

Referring now to the drawings, I0 designates the body of the carburetorwhich may be in tubular or type form and comprises the body part ofvthedevice. As shown, the bodyv part I8 may be arranged with its axis.in vertical position and provided at its lower end with a flange II forattachment to the intake manifold of an internal combustion engine. Athrottle valve I2, of the butterfly type, may be disposed in the lowerend of the tubular body II) for controlling the passage of thekmixtureto the manifold in the ordinary manner.

The upper end of the tubular body I0 may be connected to an air supplypipe I 3-which may lead from an air cleaner or the like and which ispreferably connected to the body I 0-by a bell and spigot connection asshown providing a seating shoulder I4 upon which is supported a passagereduction disc I5 having a central opening I6 of reduced diameter ascompared to that of the feed pipe I3 and the body I Il. The disc I5 isadapted to stabilize the flow of air downwardly through the tubular bodyI0. A screen I1 may be disposed upon the shoulder I4 beneath the discI5for the purpose of intercepting the passage of dust and other foreignparticles into the body II) of the carburetor.

At one side of the body I0, the carburetor is provided with the usualbowl or container I8 of suitable size to receive a desired quantity ofthe liquid fuel to be used. The bowl I8 is provided' in its bottom withar suitable drain plug I9 by means of whichxsediment collecting in thebottom of the bowl may be removed from time to time. The liquid fuel isfed through the top of the bowl I8 by a suitable pipe connection 20which opens downwardly through the top of the bowl and is providedwith adownwardly facing valve seat 2| against'which aneedle valve 22 isadapted to seat when raised. The needle valve 2| bears at itslowerend'upon a float 23 which is connected bya hinge 24 to one side of thebowl I8 and is adapted'to swing on the lhinge 24 when raised and loweredby changes in the surface level of the fuel in the bowl. Thus, the ioat25 and valve 22` maintain a predetermined constant surface llevel oftheliquid fuel in thev bowl I8. The bowl I 8 may be supported upon the bodyIllbybracket arms 26fand 21 which extend outwardly from the body IIJ andengage the upper and lower portions of the bowl.

vDisposed at preferably the opposite side of the body portion I0 vis avapor forming chamber 28 which is connected by a pipe 29 to the bowl I8.The pipe 29 opens into the bowl at a point below the normal surfacelevel ofthe liquid fuel and opens into the lower portion of the chamber28 so as to maintain in the lower portionY of the chamber a surfacelevel of the liquid fuel equal to that in the bowl I8.

Thus, a small quantity of the liquid fuel is maintained in the chamber28 lin the lower end thereof, and the upper end of the chamber is leftfree for the accumulation of vapor from the liquid fuel. Extendingaxially through the chamber 28 is a tube 30 which is provided in oneside with an opening 3I leading to the interior ofthe chamber 28 at apoint below its normal surface level of liquid so that the liquid fuelmay pass into the tube 30. A closed tube 32 is connected to the tube3i]V at its lower end and extends a suitable distance to the exhaustmanifold 33 cf an internal combustion engine, the tube 32 being closedAat its lower end andbeing externally threaded vfor adjustable engagementthrough the wall of the exhaust manifold or pipe. Thus, the lower closedend of the tube 32 may be heated by the exhaust gases passing throughthe pipe 33, or any other suitable heating means may be provided for thetube 33.

The upper end of the tube 30 is connected to a valve casing 34 whichcarries an adjustable valve 35 adapted to seat against the upper end ofthe tube 30 to close it, and which may be set to maintain an opening ofdesired size at the top of the tube. A vapor nozzle 36 is connected tothe valve casing 34 beyond the Valve 35 and projects through theadjacent wall of the tubular body Il) and is provided with a relativelylong end 31 bent at an angle to the body of the nozzle 36 and whichextends toward the lower outlet end of the tubular body and is open atits end.

For the purpose of admitting a small amount of air to the upper portionof the tube 30, above the surface level of the liquid fuel, an air valvecasing 38 is mounted in one side of the chamber 28 and opens into oneside of the tube 38 at a point above the normal surf-ace level of theliquid fuel therein. The air valve casing 38 carries a controlling valve39 which may be threaded in the casing and adjusted relatively to thevalve seat of an air port 40 in the bottom of the casing 38. The tube 30is therefore vented at its upper end so as to prevent an air locktherein incident to the accumulation of vapor in the top of the tube. Itis found essential to locate the air inlet device 38 closely adjacent tobut above the normal surface level of the liquid fuel in the chamber 28so that the air admitted through the valve 38 may properly Vent theupper vapor chamber and allow the accumulating vapor to freely escapethrough the upper vapor valve 34.

In the operation of the carburetor, the air is drawn downwardly by theaction of the internal combustion engine through the air pipe I3 andthrough the disc I5, the latter insuring a steady ow of air through thebody I0, particularly when the engine is idling or operated atrelatively slow speeds. The air passing through the disc I5 expands andtravels uniformly throughout the cross sectional area of the body I0throughout the length thereof and at all times creates the desiredpressure at the open end 31 of the vapor nozzle 36.

The liquid fuel passes from the bowl I8 through the pipe 28 to thechamber 28 and maintains the desired surface level of the liquid fuel inthe chamber. The liquid fuel passes through the opening 3l into thetubes 30 and 32, and when the latter is heated the heat is transmittedthrough the liquid fuel to the upper part of the fuel within the chamber28 and the vapor from the liquid fuel accumulated in the upper end ofthe tube 30. Any vapor pressure within the upper end of the chamber 28about the tube 30 exerts a desired pressure against the upper surface ofthe fuel in the chamber and consequently augments Iand assists in theejection of the vapor upwardly through the vapor valve 34. The Vaporpasses the valve 34 at the desired rate, determined by the adjustment ofthe valve 35, and enters the valve nozzle 36 from which it is admixedwith the column of air flowing outwardly through the hollow body Ill.

The liquid fuel is thus delivered into the mixing chamber or body part I0 in the form of a vapor which is relatively heavy and which thusreadily admixes with the air before the mixture reaches the throttlevalve I2. The air vent or valve 38 prevents the lifting or drawing ofthe liquid fuel upwardly into the vapor valve 34 but the amount of airthrough the valve 38 is so controlled as not to chill or otherwisedestroy the effect of the relatively heavy vapor formation in the upperend of the tube.

It is of course understood that the bowl I8 as well as the chamber 28may be connected 01' constructed otherwise than as shown, the importantfeatures being the relation of the parts to maintain the desired surfacelevel of the liquid fuel in the chamber 28 and to feed the vapor formedby the heating of the fuel in the pipe 30 directly into the mixingchamber.

By means of this construction at no time is the unvaporized liquid fueladmitted to the mixing chamber so that a relatively uniform mixture isprovided at the throttle valve and the mixture is raised to the properworking temperature by the heat of the vapor which passes through thenozzle 36. y

I do not wish to be restricted to the size, form and proportions of thevarious parts, and obviously changes could be made in the constructionherein described without departing from the spirit of the invention, itbeing only necessary that such changes fall within the scope of theappended claims.

What is claimed is:-

1. A carburetor comprising a mixing chamber having a throttle valve atits lower end and an air intake at its upper end and adapted forconnection with the intake manifold of an internal combustion engine, afuel supply bowl, a vapor chamber, means connecting the supply bowl withthe vapor chamber, means for maintaining a predetermined surface levelof liquid fuel in the bowl and chamber, a threaded air inlet valveconnected to the vapor chamber, a heating tube connected to the chamberfor receiving liquid fuel therefrom and adapted at its lower end portionfor insertion in the exhaust manifold of the engine for heating the fuelin the tube and chamber and vaporizing the fuel in the upper end of thetube and chamber, a vapor valve mounted 0n the upper end of the chamberfor controlling the outlet of vapor therefrom, and a nozzle leading fromthe vapor valve and opening axially and downwardly into said mixingchamber for admixture of the vapor with air passing through the mixingchamber.

2. A carburetor comprising a, tubular body open at its upper end toreceive air and adapted for connection at its lower end to the intakemanifold of an internal combustion engine, a liquid fuel supply bowldisposed at one side of the tubular body for maintaining a predeterminedsurface level of liquid fuel in the bowl, a vaporizing chamber connectedto the bowl for maintaining the said surface level of the liquid fuel inthe lower end of the chamber, a threaded air inlet for said chamber, aheating tube extending from said chamber to receive liquid fueltherefrom and adapted at its lower end portion for insertion in theexhaust manifold of the engine for vaporizing the fuel for accumulationin the upper end of the chamber, a vapor nozzle connected to the upperend of the chamber for receiving the vapor therefrom and opening axiallydownward in the tubular body for delivering the vapor into the airstream therein and an adjustable valve for said vapor nozzle.

3. A carburetor comprising a mixing tube having a throttle valve at oneend and an air intake at its opposite end, a oat chamber at one side ofsaid mixing tube, a vaporizing chamber exteriorly of the tube andconnected to the float chamber for maintaining a surface level of liquidin the vaporizing chamber equal to the surface level of the liquid inthe float chamber, adjustable valve means controlling the passage of airto the vaporizing chamber, a heating tube extending downwardly from thevaporizing chamber for connection through the side of an exhaustmanifold for heating fuel from the vaporizing chamber, a nozzle leadingfrom the upper portion of the vaporizing chamber into said mixing tubeand opening toward the throttle valve and a threaded needle valvecontro-lling the opening in the nozzle.

4. A carburetor comprising a mixing chamber having a throttle valve atits lower end and an air intake at its upper end and adapted forconnection with the intake manifold of an internal combustion engine, afuel supply bowl, a vapor chamber, means connecting the supply bowl withthe vapor chamber, means for maintaining a predetermined surface levelof liquid fuel in the bowl and chamber, a threaded air inlet Valveconnected to the vapor chamber, a heating tube Connected to the saidvapor chamber and receiving liquid fuel therefrom, means for heating thesaid heating tube to vaporize the liquid fuel therein, a vapor valvemounted on the upper end of the said vapor chamber for controlling theoutlet of vapor therefrom, and a nozzle leading from the vapor valve andopening axially and downwardly into said mixing chamber for admixture ofthe vapor with air passing through the mixing chamber.

5. A carburetor comprising a mixing chamber having a throttle Valve andan air intake in relatively spaced apart relation from the throttle andadapted for connection with the intake manifold of an internalcombustion engine, a fuel supply bowl, a vapor chamber, means connectingthe supply bowl With the vapor chamber, means for maintaining apredetermined surface level of liquid fuel in the bowl and chamber,adjustable intake means connected to the vapor chamber for admittingair, a heating tube connected to said Vapor chamber and receiving liquidfuel therefrom, means for heating the said heating tube to vaporize theliquid fuel therein, adjustable and outlet means disposed between theupper end of the vapor chamber and said mixing chamber for admixture ofthe vapor with air passing through the mixing chamber.

EARL D. WALLACE.

